KR102457538B1 - System and method for breakaway clutching in an articulated arm - Google Patents

Abstract

A system and method of breakaway clutching in a computer-assisted medical device includes an articulating arm having at least one first joint and a control unit coupled to the articulating arm and having at least one processor. The control unit operates each of the first joints in multiple states. The multi-state includes a locked state in which movement of each first joint is restricted, and a float state in which movement of each first joint is permitted. the control unit switches the one or more second joints selected from the first joint from the locked state to the float state when the stimulus for the second joint exceeds the one or more unlock thresholds, wherein the respective velocity of the second joint is at least one Transitions the second joint from the float state to the lock state when it is below the lock threshold.

Description

SYSTEM AND METHOD FOR BREAKAWAY CLUTCHING IN AN ARTICULATED ARM

Related applications

This disclosure claims priority to U.S. Provisional Patent Application No. 61/954,120, filed March 17, 2014, entitled "System and Method for Breakaway Clutching in an Articulated Arm," which is incorporated herein by reference in its entirety. do.

technical field

FIELD OF THE INVENTION The present disclosure relates generally to the operation of devices with articulating arms, and more particularly to breakaway clutching of articulating arms.

More and more devices are being replaced by autonomous and semi-autonomous electronic devices. This is particularly true in hospitals today, where large arrays of autonomous and semi-autonomous electronic devices are being found in operating rooms, intervention rooms, intensive care units, emergency rooms, etc. For example, glass and mercury thermometers are being replaced by electronic thermometers, intravenous drip lines now include electronic monitors and flow regulators, and traditional handheld surgical instruments are being replaced by computer-assisted medical devices.

These electronic devices present both advantages and challenges to the person who operates them. Most of these electronic devices are capable of autonomous or semi-autonomous operation of one or more articulating arms and/or end effectors. Before these articulating arms and their end effectors can be used they are typically moved to or near a desired working position and orientation. Such movement may be performed by teleoperation or remote operation using one or more user input controls. As the complexity of these electronic devices increases and articulating arms include a significant number of degrees of freedom, teleoperational movement to a desired working position and orientation can become complex and/or time consuming. To simplify this task, some articulating arms include a clutched or float state in which one or more of the brakes and/or actuators on the joints of the articulating arms are released, which allows the operator to directly control the position and position of the articulating arm. / or allow manual change of orientation. In this way, the articulating arm can be quickly and easily positioned and/or oriented as desired. The clutch or float state is primarily engaged by manually activating one or more clutch controls on the articulating arm and/or selecting the clutch or float state at the operator console. Manual activation of this kind may be inconvenient and/or unwise.

Accordingly, improved methods and systems for clutching articulating arms are desirable.

US Patent Application Publication No. 2014-0052154

In accordance with some embodiments, a computer-assisted medical device includes an articulating arm having one or more first joints and a control unit coupled to the articulating arm and having one or more processors. The control unit operates each of the first joints in multiple states. The multi-state includes a locked state in which movement of each first joint is restricted, and a float state in which movement of each first joint is permitted. The control unit is further configured to transition the one or more second joints selected from the first joint from the locked state to the float state when the stimulus for the second joint exceeds the one or more unlock thresholds, wherein each velocity of the second joint is one The second joint is switched from the float state to the locked state when it is lower than the above lock threshold.

In accordance with some embodiments, a method of controlling motion in a medical device includes actuating each of one or more first joints of an articulating arm of the medical device in one of multiple states. The multi-state includes a locked state in which movement of each joint is restricted, and a float state in which movement of each joint is permitted. The method also includes determining a stimulus for at least one second joint selected from the joint, transitioning the second joint from a locked state to a float state when the stimulus exceeds one or more unlock thresholds; determining each velocity, and transitioning the second joint from the float state to the locked state when the respective velocity of the second joint is below one or more lock thresholds.

In accordance with some embodiments, a non-transitory machine-readable medium comprising a plurality of machine-readable instructions, when executed by one or more processors associated with the medical device, is adapted to cause the one or more processors to perform the method. will do The method includes actuating each of one or more first joints of an articulating arm of a medical device in one of multiple states. The multi-state includes a locked state in which movement of each joint is restricted, and a float state in which movement of each joint is permitted. The method also includes determining a stimulus for one or more second joints selected from the first joint, transitioning the second joint from a locked state to a float state when the stimulus exceeds one or more unlock thresholds, a second determining a respective velocity of the joint, and transitioning the second joint from the float state to the locked state when the respective velocity of the second joint is below one or more lock thresholds.

1 is a simplified diagram of a computer-assisted system in accordance with some embodiments.
2 is a simplified diagram illustrating an articulating arm in accordance with some embodiments.
3 is a simplified diagram of a method of breakaway clutching in accordance with some embodiments.
Elements with the same designation in the drawings have the same or similar function.

In the description that follows, specific details are set forth and describe some embodiments in accordance with the present disclosure. However, it will be appreciated by those skilled in the art that some embodiments may be practiced without some or all of these specific details. The specific embodiments disclosed herein are to be considered illustrative and not restrictive. A person skilled in the art may realize other elements within the scope and spirit of the present disclosure, even if not specifically described herein. In addition, to avoid unnecessary repetition, one or more features shown and described in connection with one embodiment may be included in another embodiment unless specifically described otherwise or if one or more features render the embodiment non-functional.

1 is a simplified diagram of a computer-assisted system 100 in accordance with some embodiments. As shown in FIG. 1 , computer-assisted system 100 includes device 110 having one or more movable or articulating arms 120 . Each of the one or more articulating arms 120 may support one or more end effects. In some examples, device 110 may be consistent with a computer-assisted surgical device. One or more articulating arms 120 each provide support for surgical instruments, imaging devices, and/or the like. Device 110 may be further coupled to an operator workstation (not shown), which includes one or more main controls for operating device 110 , one or more articulating arms 120 , and/or an end effector. can do. In some embodiments, the device 110 and operator workstation may correspond to the da Vinci® Surgical System commercialized by Intuitive Surgical, Inc. (Sunnyvale, Calif.). In some embodiments, computer-assisted surgical devices having other configurations, fewer or more articulating arms, and/or the like may be used with the computer-assisted system 100 .

The device 110 is coupled to the control unit 130 via an interface. The interface may include one or more cables, connectors, and/or buses, and may further include one or more networks having one or more network switching and/or routing devices. The control unit 130 includes a processor 140 coupled to a memory 150 . The operation of the control unit 130 is controlled by the processor 140 . And, while the control unit 130 is shown with only one processor 140 , the processor 140 may include one or more central processing units, multi-core processors, microprocessors, microcontrollers, digital signals in the control unit 130 . It is understood that it may represent a processor, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), and/or the like. Control unit 130 may be implemented as a standalone subsystem and/or board added to a computing device or as a virtual machine. In some embodiments, the control unit may be included as part of an operator workstation and/or may be operated separately from the operator workstation but in concert with the operator.

Memory 150 may be used to store software executed by control unit 130 and/or one or more data structures for use during operation of control unit 130 . Memory 150 may include one or more types of machine-readable media. Some common forms of machine-readable media are floppy disks, flexible disks, hard disks, magnetic tape, any other magnetic medium, CD-ROM, any other optical medium, punch card, paper tape, any with a hole pattern. may include other physical media, RAM, PROM, EPROM, FLASH-EPROM, any other memory chip or cartridge, and/or any other medium suitable for reading by a processor or computer.

As shown, the memory 150 includes a motion control application 160 that may be used to support autonomous and/or semi-autonomous control of the device 110 . Motion control application 160 receives location, motion and/or other sensor information from device 110 , exchanges location, motion, and/or collision avoidance information with other control units associated with other devices, and/or device 110 ), articulating arm 120 and/or one or more application programming interfaces (APIs) for planning and/or assistance in planning of end effectors of device 110 . And, although the motion control application 160 is depicted as a software application, the motion control application 160 may be executed using hardware, software, and/or a combination of hardware and software.

In some embodiments, computer-assisted system 100 may be found in operating rooms and/or intervention rooms. And, while the computer-assisted system 100 includes only one device 110 with two articulated arms 120 , one of ordinary skill in the art would appreciate that the computer-assisted system 100 is similar to and/or similar to the device 110 . It will be appreciated that it may include any number of devices having articulating arms and/or end effectors of different designs. In some examples, each of the devices may include fewer or more articulating arms and/or end effectors.

2 is a simplified diagram illustrating an articulating arm 200 in accordance with some embodiments. For example, articulating arm 200 may be part of one of articulating arms 120 in device 110 . As shown in FIG. 2 , the articulating arm 200 includes various links and joints. It is coupled to the platform 210 at the most proximal end of the articulating arm 200 . In some examples, platform 120 may be distal to additional joints and links (not shown) from computer-assisted devices. A series of set-up joints and links 220 are coupled to the platform 210 . The setup joint and link 220 are rotationally coupled to the platform 210 via a first setup linkage joint 222 . In some examples, additional set-up links and joints for other articulating arms (not shown) may be rotationally coupled to platform 210 using additional first set-up linkage joints. A setup base linkage 224 coupled to a proximal end of a setup linkage extension link 226 through a first setup linkage prismatic joint 228 is coupled to a first setup linkage joint 222 . The distal end of the setup linkage extension link 226 is coupled to the proximal end of the setup linkage vertical link 230 via a second setup linkage prismatic joint 232 . The distal end of the setup linkage vertical link 230 is rotationally coupled to the proximal end of the support link 234 via a second setup linkage joint 236 . The first rotary joint 238 is coupled to the distal end of the support link 234 . The first rotational joint 238 provides an additional link distal to the first rotational joint 238 and rotational control over the joint. In some examples, the central axis 250 of the first rotational joint 238 may be aligned with a remote center 290 that may be fixed in position during teleoperation of the articulating arm 200 .

The coupling link 240 couples the first rotary joint 238 to the first rotary joint 242 . The second rotary joint 240 is coupled to the yaw joint 252 via a yaw link 254 . A parallelogram pitch mechanism 260 is coupled distally to the yaw joint 252 . A first pitch link 262 at the proximal end of the parallelogram pitch mechanism 260 couples the yaw joint 252 to the first pitch joint 264 . The second pitch link 266 couples the first pitch joint 264 to the second pitch joint 268 . The third pitch link 270 couples the second pitch joint 268 to the third pitch joint 272 . An instrument carriage is coupled to a third pitch joint 272 and includes an instrument shaft 280 . One or more end effectors may be coupled to the distal end of the instrument shaft 280 . In some examples, the parallel pitch mechanism 260 may be controlled to maintain the instrument shaft 280 in alignment with the remote center 290 .

As shown in FIG. 2 articulating arm 200 includes a plurality of linkages 224, 226, 230, 234, 240, 254, 262, 266, 270, and 280, their relative positions and/or orientations. can be adjusted using multiple prismatic joints 228 and 232 and multiple rotary joints 222 , 236 , 238 , 242 , 262 , 264 , 268 , and 272 . Each of the prismatic and rotational joints may include one or more sensors for sensing position, rotation, movement, force, torque, and/or the like for the respective joint.

Each of the various joints can be either a non-actuated joint or a driven joint, depending on the desired ability to control the articulating arm 200 . In some examples, the non-actuated joint may not include any actuators, such that it may not be operated via teleoperational and/or motion control commands from the control unit of the articulating arm 200 . In some examples, the non-actuated joint may include a brake, which allows the control unit to prevent and/or limit motion at the non-actuated joint. By way of example, joints 228 , 232 and/or 236 of FIG. 2 may be non-actuated joints. In some examples, the actuated joint may include one or more actuators capable of controlling the motion of the actuated joint through teleoperation and/or motion commands. In some examples, the driven joint may further include a brake.

In some embodiments, the various joints and links in the articulating arm 200 may be positioned in a locked state to prevent unwanted movement, in which position each of the non-actuated joint brakes is activated and the Each is commanded to hold the actuated joint in a commanded position. In some examples, the locked state may further prevent unwanted motion due to gravity acting on the articulating arm 200 . Although not shown in FIG. 2 , the articulating arm 200 may include one or more clutch buttons or a control unit. In some examples, the clutch button may be located at various locations along the instrument carriage. In some examples, additional clutch controls may be activated via operator controls in the operator console. By activating one or more of the clutch buttons or controls, one or more joints of the articulating arm may be switched from a locked state to a clutch or float state, wherein at least a portion of the non-actuated joint brake may be at least partially released; At least a portion of the actuated joint actuator may permit motion of the joint away from the commanded position. For example, activation of a clutch button located on articulation arm 200 may place articulation arm 200 in a float state, while another portion of the computer-assisted device coupled to platform 210 locks. state can be maintained. While the joint of the articulating arm 200 is in the float state, an operator may manually position and/or orient the articulating arm 200 to a desired working position and orientation.

In some embodiments, manual activation of the clutching mechanism of the articulating arm 200 may not always be practiced and/or prudent. In some instances, the location of the clutch button or control may not be convenient for easy activation by an operator. In some examples, the operator may not have free fingers and/or hands capable of actuating the clutch control. In some instances, cooperation of clutch controls with other operators located at the operator console may be enabled and/or disabled. In some instances, an operator may not be able to actuate the clutch control without destroying an established sterile site around a portion of the articulating arm 200 . Accordingly, it would be beneficial for at least a portion of the articulating arm 200 to enter the float state without activation of the clutch control by the operator.

In some embodiments, movement of the articulating arm 200 may be desirable without manual clutch activation. In some examples, a sudden collision may occur between an operator, patient, and/or object and one or more links and/or joints of articulating arm 200 . In some instances, a sudden impact may result in a wound to an operator, a wound to a patient, an injury to an object, and/or damage to an articulating arm 200 due to the rigid position and/or orientation being held by the articulating arm 200 . can bring In some examples, detecting a sudden impact and being able to automatically enter the articulating arm 200 into a float state may reduce operator wounds, patient wounds, object damage, and/or articulation arm 200 damage. have.

3 is a simplified diagram of a method 300 of breakaway clutching in accordance with some embodiments. When one or more of the processes 310 - 360 of method 300 are operated at least in part by one or more processors (eg, the processor 140 of the control unit 130 ), the one or more processors cause the processor 310 - 360) in the form of executable code stored on a non-transitory, tangible, machine-readable medium, capable of performing one or more of the following: In some embodiments, method 300 may be performed by an application, such as motion control application 160 .

In step 310, the locked state is entered. The joints of the articulating arms, such as articulating arms 120 and/or 200, may be positioned in the locked state by default. Movement of the articulating arm in the locked state activates a brake at each of the non-actuated joints of the articulating arm and moves each of the actuated joints of the articulating arm into their respective commanded positions using a corresponding actuated joint actuator. can be prevented and/or reduced by maintaining

At 320 , an external stimulus for one or more joints is determined. One or more sensors associated with each of the joints of the articulating arm are periodically read and/or monitored to determine whether there is any external stimulus applied to the one or more joints of the articulating arm. In some examples, linear sensors associated with prismatic joints and/or rotation sensors associated with rotary joints are monitored to determine the actual position of each joint. In some examples, a position error may be determined based on a difference between an actual position and a commanded position in a driven joint and/or a braked position in a non-driven joint. In some examples, the position error may be converted to an approximate force and/or torque for each joint by using one or more kinematic models, inverse Jacobian transpositions, and/or control models for each joint. In some examples, the force and/or torque for each joint may be measured using force and/or torque sensors that each monitor each joint. In some examples, the joint speed of the driven joint may also be determined using one or more speed sensors associated with the driven joint or numerically based on changes in the actual position of the driven joint.

At process 330 , it is determined whether an external stimulus to any of the joints exceeds an unlock threshold. Each external stimulus value of the joint determined during process 320 is compared to one or more unlock thresholds to determine whether any of the unlock thresholds are exceeded. In some examples, the joint of the articulating arm may transition to a float state using process 340 when any one of the external joint stimulus values exceeds the respective unlock threshold. In some examples, a joint of an articulating arm may transition to a float state when a combination of two or more of the external joint stimulus values exceeds a respective unlock threshold. In some examples, a joint of an articulating arm may transition to a float state when a weighted and/or unweighted aggregation of external stimulus values from two or more joints exceeds a composite unlock threshold. In some examples, the aggregation may include mean, median, sum of squares, minimum, maximum, and/or the like.

In some examples, each of the unlock thresholds for each joint may be different depending on the location and/or purpose of each joint in the articulating arm. In some examples, the unlock threshold may be adjusted based on the current pose, position, and/or orientation of the articulating arm. In some examples, the unlock threshold for each joint may be adjusted and/or disabled when each joint has crossed a soft stop proximate to the end of a possible motion for each joint. In some examples, the float state may be activated by default when each joint has crossed a soft stop. In some examples, the determination of whether the external stimulus exceeds a threshold may be limited to a subset of joints in the articulating arm. In some examples, an external stimulus to a braking, non-actuated joint may not be monitored during process 320 and may not have a corresponding unlock threshold. In some examples, the unlock threshold may be adjusted based on the size and/or mass of the articulating arm. In some examples, the unlock threshold may be large enough to avoid an abrupt transition to the float state due to the force of gravity and/or an error in the joint sensor.

In some examples, the unlock threshold may correspond to a threshold value associated with a position error between the actual position of the joint and the commanded and/or broken position of the joint. In some examples, the threshold value may be between 0.02 and 5 millimeters for a prismatic joint. In some examples, the threshold value may be between 0.03 and 0.5 degrees for the rotary joint. In some examples, the one or more unlock thresholds may correspond to a force and/or torque applied to the joint, measured and/or determined during process 320 . In some examples, the threshold value may be between 1 and 30 N for force on a prismatic joint. In some examples, the threshold value may be between 1 and 30 N-m for torque on the rotary joint. In some examples, the threshold value may exceed the force and/or torque saturation value for the joint.

In some embodiments, the unlock threshold must be exceeded for a defined period of time before transitioning the articulated arm to the float state. In some examples, a joint of an articulating arm may transition to a float state when each external stimulus value continuously exceeds a corresponding unlocking threshold for a defined period of time. In some examples, the joint of the articulating arm may transition to a float state when the aggregation, eg, average, of each external stimulus value exceeds the respective stimulus value over a defined period of time. In some examples, sliding windows and/or exponential smoothing may be used to determine the aggregation. In some examples, filters may be used on sensed external stimuli that emphasize mid-frequency to better separate disturbances due to human intent from disturbances due to gravity and other environmental factors that may be present at low frequencies. In some examples, the mid-frequency may extend from approximately 0.01 Hz to 10 Hz. In some instances, separate wave element transformations may be used in place of or in combination with filters to better isolate human-intended disturbances. In some examples, the defined time period may be set by the operator. In some examples, the defined period of time may be between 50 and 1500 milliseconds. In some examples, the defined period of time may be different from when the breakaway clutching is first activated, such that residual momentum of the articulating arm due to static disturbances from the environment confounding other recently completed motions and/or user input. A sudden transition to the float state caused by In some instances, the locked state must be established in an external stimulus below the unlock threshold for a defined period of time before the first breakaway clutching is activated, such that when the articulating arm is undocked from the patient, the end effector articulates. An abrupt transition to the float state may be avoided when attached to or removed from the arm, and/or possibly due to temporary circumstances, such as the like. In some examples, the defined time may be extended by an additional 100 to 250 milliseconds after breakaway clutching is enabled.

When the external stimulus does not exceed one or more unlock thresholds, the external stimulus is determined again using process 320 . When the external stimulus exceeds one or more unlock thresholds, the joint of the articulating arm transitions to a float state using process 340 .

In step 340, the float state is entered. At least one of the joints of the articulating arm is positioned in a float state, which allows free and/or near-free movement of the joint. In some examples, the joint positioned in the float state may be a subset of the joints in the articulating arm. In some instances, this allows applying breakaway clutching to a portion of an articulated arm that is subjected to an external stimulus. In some examples, the brakes for each of the non-actuated joints positioned in the float state may be released to allow movement of each of the non-actuated joints. In some examples, each of the actuated joints positioned in the float state may be commanded to move to an actual position determined during process 320 or while the actuated joint remains in the float state. In some examples, each of the actuated joints positioned in the float state may also be commanded to match the joint velocity determined during process 320 or while the actuated joint remains in the float state. In some examples, setting the command position of the feedback controller of the driven joint to the actual position and/or setting the command speed of the feedback controller to the actual joint speed causes the driven joint to perceive that it is moving freely, and gravity compensation is Also, when being applied, it also makes the perception of apparent weightlessness.

In some embodiments, the movement of the joint in the float state may be damped. To reduce and/or prevent unrestricted and/or unruly movement of the articulating arm while in the float state, one or more of the joints positioned in the float state may be subject to some form of braked motion. For example, it may be undesirable for an articulating arm that has undergone a strong external stimulus, such as a severe impact, to move away from the strong external stimulus without some limitations. Restraining the clutched movement may reduce the risk of injury and/or damage caused by a rapidly moving articulating arm. In some examples, a braked action may be performed on a non-actuated joint by partially disengaging the brake, thereby placing a drag force on the movement of the non-actuated joint. In some examples, the brake may be partially released by controlling one or more voltage, current, duty cycle, and/or the like of a signal used to control the brake. In some examples, the braked motion is by commanding the driven joint to move a portion of a distance behind its actual position based on the direction of motion, by increasing the derivative constant in the feedback controller without substantially affecting the stability margin, and/or This can be done for the driven joint by introducing a backward current and/or voltage to the actuator of the driven joint to mimic the resistive force and/or torque. In some examples, a braked motion may be performed on the driven joint by instructing the speed of the driven joint to be lower than the joint speed determined during process 320 or while the driven joint remains floated. In some examples, the braked motion may be adjusted taking into account the current pose, position, and/or orientation of the articulating arm, the size and/or mass of the articulating arm, and/or the like.

In some embodiments, one or more of the joints of the articulating arm not positioned in the float state may be subject to motion restrictions. In some examples, a joint not positioned in the float state may be commanded in response to detected movement of a joint positioned in the float state. In some examples, a joint that is not positioned in the float state may be commanded in one or more positions and/or orientations. In the example of FIG. 2 , one or more of the joints in the parallelogram pitch mechanism 260 may be commanded to maintain the intersection of the instrument shaft 280 with the central axis 250 at the remote center 290 .

In step 350 a joint velocity is determined. One or more sensors associated with each of the joints of the articulating arm are periodically read and/or monitored to determine the velocity of each of the joints in the float state. In some examples, the change in linear and/or rotational position between two successive monitoring intervals is used to estimate the joint velocity. In some examples, numerical and/or other differential techniques may be used to determine joint velocity from the sensed position. In some examples, a speed sensor on the joint may be monitored.

At process 300 , it is determined whether the joint velocity has fallen below a lock threshold. During breakaway clutching, the joint of the articulating arm remains floated as long as continued motion of the articulating arm is detected. The joint velocity determined during process 350 is compared to one or more lock thresholds to determine whether any continued motion is detected in the articulating arm. In some examples, each of the joint velocities may be compared to a corresponding lock threshold. When each of the joint velocities is below its corresponding locking threshold, a lack of motion is detected and the joint of the articulating arm is transitioned to the locked state using process 310 . In some examples, a joint of an articulating arm can be transitioned to a locked state using process 310 when the weighted and/or unweighted aggregation of joint velocities from each of the joints is below the composite lock threshold. have. In some examples, the aggregation may include mean, median, sum of squares, minimum, maximum, and/or the like.

In some examples, each of the lock thresholds for each joint may be different depending on the location and/or purpose of each joint in the articulating arm. In some examples, the lock threshold may be adjusted based on the current pose, position, and/or orientation of the articulating arm. In some examples, the lock threshold for each joint may be adjusted and/or disabled when each joint has crossed a soft stop near the end of a possible motion for each joint. In some examples, the locked state may be activated by default when each joint has crossed a soft stop. In some examples, the determination of whether the joint velocity is below the lock threshold may be limited to a subset of joints in the articulating arm. In some examples, the lock threshold may be adjusted based on the size and/or mass of the articulating arm. In some examples, the lock threshold may be large enough to avoid an abrupt transition to lock due to an error in the joint sensor.

In some examples, the lock threshold may be 0.1 to 10 millimeters per second for a prismatic joint. In some examples, the threshold value may be between 0.25 and 10 degrees per second for the rotary joint.

In some embodiments, the joint velocity must remain below the lock threshold for a defined period of time before transitioning the joint of the articulating arm to the locked state. In some examples, a joint of an articulating arm may transition to a locked state when the joint velocity is continuously below a corresponding locking threshold for a defined period of time. In some examples, a joint of an articulating arm may transition to a locked state when an aggregate, eg, average, of each joint velocity over a defined period of time is below their respective lock threshold. In some examples, sliding windows and/or exponential smoothing may be used to determine the aggregation. In some examples, the defined time period may be set by the operator. In some examples, the defined period of time may be between 100 and 200 milliseconds.

When the joint velocity remains above the lock threshold, the joint velocity is determined again using process 350 . When the joint velocity is below the lock threshold, the joint of the articulating arm transitions to the locked state using process 310 .

As discussed above and further emphasized herein, FIG. 3 is merely an example and should not unduly limit the scope of the claims. Those skilled in the art will recognize many variations, modifications, and variations. According to some embodiments, the breakaway clutching of method 300 may be disabled during certain modes of operation of the articulating arm. In some examples, the breakaway clutching may be disabled when the articulating arm is in a rigidly locked state during storage and/or when the cart to which the articulating arm is mounted is being transferred between positions. In some examples, breakaway clutching can be disabled when the articulating arm is in an actuated teleoperational mode and/or when performing a commanded action, such as when docked to a patient. In some instances, breakaway clutching disabled during actuated actuation reduces the likelihood that manual interference and/or impact by the articulating arm will interfere with tele actuation and/or commanded actuation, thus damaging the object being steered and and/or reduce the further likelihood of causing injury to a patient for whom arthroscopic cancer is being used. In some examples, the breakaway clutching may be adjusted, propelled, or disengaged when any of the joints in the articulating arm have passed the soft stop position.

Some examples of control units, such as control unit 130 , are executable by one or more processors (eg, processor 140 ) that, when operated by, enable one or more processors to perform the processes of method 300 . may include a non-transitory, tangible, machine-readable medium containing code. Some common forms of machine readable media that can include the process of method 300 are, for example, floppy disks, flexible disks, hard disks, magnetic tapes, any other magnetic media, CD-ROMs, any other optical media, punch cards, paper tape, any other physical media having a hole pattern, RAM, PROM, EPROM, FLASH-EPROM, any other memory chip or cartridge, and/or any other suitable for reading by a processor or computer. is the medium

While exemplary embodiments have been shown and described, a wide range of modifications, changes, and substitutions are contemplated in the foregoing disclosure, and in some instances some features of the embodiments may be utilized without corresponding use of other features. Those skilled in the art will recognize many variations, alternatives, and modifications. Accordingly, it is recognized that the scope of the present invention should be limited only by the following claims, which should be broadly construed in a manner consistent with the scope of the embodiments disclosed herein.

Claims (15)

Articulating arm including a first joint, wherein the first joint is operable in a locked state or operable in a float state, movement of the first joint is limited in the locked state, and movement of the first joint is operable in a float state allowed -; and
A control unit coupled to the articulating arm and including one or more processors.
A computer-assisted device comprising:
The control unit is:
transition the first joint from the locked state to the float state when the stimulus associated with the first joint exceeds the first unlock threshold;
transition the first joint from the float state to the locked state when a velocity associated with the first joint falls below the first lock threshold;
wherein the first unlocking threshold is based on a position of the first joint in the articulating arm or the first locking threshold is based on a position of the first joint in the articulating arm. The method of claim 1 , wherein the control unit further comprises:
configured to adjust the first unlock threshold based on the pose, position, or orientation of the articulating arm; or
and adjust the first lock threshold based on the pose, position, or orientation of the articulating arm. The method of claim 1,
the first unlock threshold is based on whether the first joint has crossed a position proximate to the end of a possible motion for the first joint; or
The first lock threshold is based on whether the first joint has crossed a position proximate to the end of a possible motion for the first joint; or
and the control unit is configured to transition the first joint from the locked state to the float state when the first joint has crossed a position proximate to an end of a possible motion for the first joint. The method of claim 1 , wherein the stimulus comprises:
corresponding to a position error between the commanded position of the first joint and the current position of the first joint, wherein the first joint is a driven joint; or
corresponding to a position error of the first joint between the braked position of the first joint and the current position of the first joint, wherein the first joint is a non-driven joint; or
a computer-assisted device corresponding to a force or torque for the first joint. The method of claim 1 , wherein the control unit comprises:
transition the first joint from the locked state to the float state when the stimulus aggregation for the first joint over a defined period of time exceeds the first unlock threshold; or
configured to transition the first joint from the locked state to the float state when the stimulus to the first joint continuously exceeds the first unlock threshold for a defined period of time; or
and hold the first joint in the locked state for a predetermined period of time prior to first transitioning the first joint to the float state. 6. The method according to any one of claims 1 to 5, wherein the control unit further comprises;
configured to transition the first joint from the locked state to the float state when a stimulus associated with the second joint of the articulating arm exceeds a second unlock threshold; or
and transition the first joint from the locked state to the float state when the aggregation of the stimuli associated with the second joint and the stimuli associated with the first joint exceed a composite unlock threshold. 6. The method according to any one of claims 1 to 5, wherein the control unit comprises:
transition the first joint from the float state to the locked state when the aggregate of the velocity associated with the first joint over a defined period of time is below the first lock threshold; or
and transition the first joint from the float state to the locked state when a velocity associated with the first joint is continuously below the first lock threshold for a defined period of time. 6. The method according to any one of claims 1 to 5, wherein the first joint is a non-actuated joint,
the control unit is configured to activate a brake on the first joint in the locked state; or
and the control unit is configured to at least partially release the brake on the first joint in the float state. 6. The method according to any one of claims 1 to 5, wherein the first joint is a driven joint,
the control unit is configured to hold the first joint in the commanded position in the locked state; or
the control unit is configured to command the first joint to the actual position of the first joint in the float state; or
and the control unit is configured to command the first joint at an actual velocity of the first joint in the float state. 6. The method according to any one of claims 1 to 5, wherein the control unit further comprises:
configured to prevent transition of the first joint to a float state when the articulating arm is in a defined mode of operation;
wherein the predetermined mode of operation comprises a mode selected from the group consisting of a transport mode, a teleoperation mode, a commanded mode of operation, and a patient docking mode. A non-transitory machine-readable medium comprising a plurality of machine-readable instructions adapted to, when executed by one or more processors associated with an apparatus, cause the one or more processors to perform a method, the non-transitory machine-readable medium comprising:
The device includes an articulating arm including a first joint, wherein the first joint is operable in a locked state or a float state, movement of the first joint is limited in the locked state, and movement of the first joint is in a float state. is permitted in
The method is
transitioning the first joint from the locked state to the float state when a stimulus associated with the first joint exceeds a first unlock threshold; and
transitioning the first joint from the float state to the locked state when the velocity associated with the first joint falls below the first lock threshold;
wherein the first unlocking threshold is based on a position of the first joint in the articulating arm or the first locking threshold is based on a position of the first joint in the articulating arm. 12. The method of claim 11, wherein the method comprises:
adjusting the first unlock threshold based on the posture, position, or orientation of the articulating arm; or
adjusting the first lock threshold based on the posture, position, or orientation of the articulating arm;
A non-transitory machine-readable medium, further comprising: 12. The method of claim 11, wherein the stimulus comprises:
corresponding to a position error between the commanded position of the first joint and the current position of the first joint, wherein the first joint is a driven joint; or
corresponding to a position error of the first joint between the broken position of the first joint and the current position of the first joint, wherein the first joint is a non-actuated joint; or
A non-transitory machine-readable medium corresponding to a force or torque for the first joint. 14. The method according to any one of claims 11 to 13, wherein the method comprises:
transitioning the first joint from the locked state to the float state when the stimulus aggregate for the first joint over a defined period of time exceeds a first unlock threshold; or
transitioning the first joint from the locked state to the float state when the stimulus to the first joint continuously exceeds the first unlock threshold for a predetermined period of time; or
transitioning the first joint from the locked state to the float state when the stimulus associated with the second joint of the articulating arm exceeds a second unlock threshold; or
transitioning the first joint from the locked state to the float state when the aggregate of the stimuli associated with the second joint and the stimuli associated with the first joint exceeds a composite unlock threshold; or
and holding the first joint in the locked state for a predetermined period of time prior to first transitioning the first joint to the float state. 14. The method according to any one of claims 11 to 13, wherein the method comprises:
transitioning the first joint from the float state to the locked state when the aggregate of velocities associated with the first joint over a defined period of time is below the first lock threshold; or
and transitioning the first joint from the float state to the locked state when a speed associated with the first joint is continuously below the first lock threshold for a defined period of time.

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